In connection with suction boxes in paper machines which are used for numerous functions, such as dewatering a web and guiding a wire, particular problems have been the high consumption of power and the rapid wear of the wires running over the suction box. The ribs or the common deck on a suction box is/are placed against the wire, i.e., in engagement therewith, in which connection, by the effect of the vacuum in the suction box which is applied to the wire through spaces in the deck or between the ribs, a force is produced between the wire and the ribs, which force is divided into a normal force and a friction force. The friction force between the ribs and the wire increases as a function of the vacuum in the suction box and the speed of the wire, and as a result of the friction force, intensive wear of the wire arises. This also increases the requirement of power of the suction box.
In suction box constructions in the prior art, as one solution for these problems, instead of suction boxes, suction rolls have been used, in whose connection, however, the high power loss arising from pumping has been still been problematic. Likewise, the cleaning costs and the high costs of servicing and manufacturing suction rolls have been a drawback of such constructions. Also, it is problematic that when the running speed of the wire becomes high, the consumption of power of the suction roll is increased to a large extent, and also the wear of the wire is increased, for which reasons other solutions are needed for these problems.